scholarly journals Effect of Vacuum Annealing on the Optoelectric and Morphological Properties of F16CuPc Thin Films

2012 ◽  
Vol 9 (1) ◽  
pp. 294-300 ◽  
Author(s):  
Raji Koshy ◽  
C. S. Menon
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Vacuum Annealing ◽  
Band Gap Energy ◽  
Dielectric Constants ◽  
Morphological Properties ◽  
Optical Data ◽  
Organic Transistors ◽  
Reflectivity Spectra ◽  
Electrical Study

The effect of vacuum annealing temperature on optical and electrical properties of vacuum evaporated F16CuPc thin films have been studied spectrophotometer and Kiethely electrometer respectively. The band gap energy both fundamental and excitonic remains unchanged when the annealing temperature increased. The optical constants of thin films are obtained by means of thin film spectrophotometry. From the electrical study, the activation energies of the films, in the intrinsic region and impurity region have been determined from the Arrhenious plots of lnσversus1000/T. Optical data have been obtained from both absorption and reflectivity spectra over the wavelength range 200-800 nm. The absorption coefficient α and extinction coefficient k are estimated from the spectrum. The mechanism of optical absorption follows the rule of direct transition. Using α and k, the refractive index and the dielectric constants are determined. The SEM investigations are F16CuPc thin films are expected to find application in the fabrication of optoelectronic devices such as organic transistors and LED devices.

Effect of vacuum annealing on the properties of one step thermally evaporated Sb2S3 thin films for photovoltaic applications

2021 ◽  
Author(s):  
Emna Gnenna ◽  
Naoufel Khemiri ◽  
Minghua Kong ◽  
Maria Isabel Alonso ◽  
Mounir Kanzari
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Vacuum Annealing ◽  
Xrd Analysis ◽  
Band Gap Energy ◽  
Chemical Compositions ◽  
Optical Parameters ◽  
X Ray ◽  
Vis Spectroscopy ◽  
One Step

Sb2S3 powder was successfully synthesized by solid state reaction technique using high-purity elemental antimony and sulfur. Sb2S3 thin films were deposited on unheated glass substrates by one step thermal evaporation and annealed under vacuum atmosphere for 2 hours at different temperatures 150, 200 and 250 °C. Different characterization techniques were used to better understand the behavior of the Sb2S3 material. X-ray diffraction (XRD) and Raman spectroscopy confirmed the formation of pure Sb2S3 powder with lattice parameters a = 11.07 Å, b = 11.08 Å and c = 3.81 Å. The effect of vacuum annealing temperature on the properties of the films was studied. XRD analysis revealed that as-deposited and annealed films at 150ºC were amorphous in nature whereas those annealed at T ≥ 200°C were polycrystalline with a preferred orientation along (201) plane. The crystallite size of the polycrystalline films showed a decrease from 75.8 to 62.9 nm with the increase of the annealing temperature from 200 to 250 °C. The Raman analysis showed several peaks corresponding to the stibnite Sb2S3 phase. The surface morphology of the films was examined by atomic force microscopy (AFM). The surface roughness decreases slightly as the transformation from the amorphous to the crystalline phase occurs. The chemical compositions of Sb2S3 films were analyzed by energy dispersive X-ray spectroscopy (EDS), revealing that all films were Sb-rich. The optical parameters were estimated from the transmittance and reflectance spectra recorded by UV-Vis spectroscopy. A reduction in the direct band gap energy from 2.12 to 1.70 eV with the increase of annealing temperature was also found.

scholarly journals Emergence and Evolution of Crystallization in TiO2 Thin Films: A Structural and Morphological Study

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1409
Author(s):  
Ofelia Durante ◽  
Cinzia Di Giorgio ◽  
Veronica Granata ◽  
Joshua Neilson ◽  
Rosalba Fittipaldi ◽  
...  
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Transition Metal Oxides ◽  
Annealing Temperature ◽  
Morphological Properties ◽  
Degree Of Crystallinity ◽  
Tio2 Thin Films ◽  
Force Microscopy ◽  
Heat Treated ◽  
Complementary Techniques

Among all transition metal oxides, titanium dioxide (TiO2) is one of the most intensively investigated materials due to its large range of applications, both in the amorphous and crystalline forms. We have produced amorphous TiO2 thin films by means of room temperature ion-plasma assisted e-beam deposition, and we have heat-treated the samples to study the onset of crystallization. Herein, we have detailed the earliest stage and the evolution of crystallization, as a function of both the annealing temperature, in the range 250–1000 °C, and the TiO2 thickness, varying between 5 and 200 nm. We have explored the structural and morphological properties of the as grown and heat-treated samples with Atomic Force Microscopy, Scanning Electron Microscopy, X-ray Diffractometry, and Raman spectroscopy. We have observed an increasing crystallization onset temperature as the film thickness is reduced, as well as remarkable differences in the crystallization evolution, depending on the film thickness. Moreover, we have shown a strong cross-talking among the complementary techniques used displaying that also surface imaging can provide distinctive information on material crystallization. Finally, we have also explored the phonon lifetime as a function of the TiO2 thickness and annealing temperature, both ultimately affecting the degree of crystallinity.

Band gap tuning and p to n-type transition in Mn-doped CuO nanostructured thin films

2022 ◽  
Vol 43 (1) ◽  
pp. 012801
Author(s):  
R. Rahaman ◽  
M. Sharmin ◽  
J. Podder
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Spray Pyrolysis Technique ◽  
Band Gap Energy ◽  
Dielectric Constants ◽  
X Rays ◽  
Electron Effective Mass ◽  
Mn Doping ◽  
Type Transition ◽  
Mn Doped

Abstract Here we discuss the synthesis of copper (II) oxide (CuO) and manganese (Mn)-doped CuO thin films varying with 0 to 8 at% Mn using the spray pyrolysis technique. As-deposited film surfaces comprised of agglomerated spherical nanoparticles and a semi-spongy porous structure for 4 at% Mn doping. Energy dispersive analysis of X-rays confirmed the chemical composition of the films. X-ray diffraction spectra showed a polycrystalline monoclinic structure with the predominance of the ( 11) peak. Optical band gap energy for direct and indirect transitions was estimated in the ranges from 2.67–2.90 eV and 0.11–1.73 eV, respectively. Refractive index and static dielectric constants were computed from the optical spectra. Electrical resistivity of CuO and Mn-doped CuO (Mn:CuO) thin films was found in the range from 10.5 to 28.6 Ω·cm. The tiniest electron effective mass was calculated for 4 at% Mn:CuO thin films. P to n-type transition was observed for 4 at% Mn doping in CuO films. Carrier concentration and mobility were found in the orders of 1017 cm–3 and 10–1 cm2/(V·s), respectively. The Hall coefficient was found to be between 9.9 and 29.8 cm3/C. The above results suggest the suitability of Mn:CuO thin films in optoelectronic applications.

Effect of Manganese on Titanium Thin Films Adhesion Deposited on Steel Substrates

2012 ◽  
Vol 326-328 ◽  
pp. 583-586
Author(s):  
R. Gheriani ◽  
Raouf Mechiakh
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Vacuum Annealing ◽  
Pure Titanium ◽  
Nucleation And Growth ◽  
Thin Solid Films ◽  
X Ray ◽  
Solid Films ◽  
Titanium Thin Films ◽  
Steel Substrates

The mainly property of thin solid films technologies is their adhesion to the substrates. Because of its good wear resistance and its low coefficient of friction against steel, TiC is an attractive coating material for wear applications such as bearing components. The adhesion of TiC coatings, however suffers from insufficient reproducibility, which is probably due to uncontrolled process parameters. In our work pure titanium thin films of approximately 0.6 µm in thickness were prepared on 100C6 stainless steel substrates by cathodic sputtering. The samples were subjected to secondary vacuum annealing at a temperature between 400 and 1000°C for 30 min. The reaction between substrates and thin films was characterized using an x-ray diffractometer (XRD). Surface morphology and elements diffusion evaluations were carried out by scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). The interaction substrates-thin films is accompanied by nucleation and growth of titanium carbide as a function of annealing temperature. By the SEM and EDS results, it appears clearly that the diffusion of manganese to the external layers leads to the destruction of adhesion especially at high temperatures.

Structural and Morphological Properties of HfxZr1-xO2 Thin Films Prepared by Pechini Route

2010 ◽  
Vol 644 ◽  
pp. 113-116
Author(s):  
L.A. García-Cerda ◽  
Bertha A. Puente Urbina ◽  
M.A. Quevedo-López ◽  
B.E. Gnade ◽  
Leo A. Baldenegro-Perez ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Annealing Temperature ◽  
Precursor Solution ◽  
Dip Coating ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dip Coating Technique ◽  
Scanning Electron

In this study, HfxZr1-xO2 (0 < x < 1) thin films were deposited on silicon wafers using a dip-coating technique and by using a precursor solution prepared by the Pechini route. The effects of annealing temperature on the structure and morphological properties of the proposed films were investigated. HfxZr1-xO2 thin films with 1, 3 and 5 layers were annealed in air for 2 h at 600 and 800 °C and the structural and morphological properties studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD results show that the films have monoclinic and tetragonal structure depending of the Hf and Zr concentration. SEM photographs show that all films consist of nanocrystalline grains with sizes in the range of 6 - 13 nm. The total film thickness is about 90 nm.

scholarly journals "Effect Of Thermal Annealing On The Optical Properties Of Thin Films Of Polymer Blend (PMMA:PVC:PS) "

2018 ◽  
Vol 5 (1) ◽  
pp. 1-7
Author(s):  
Ali N. Sabbar ◽  
Karar M. Talib ◽  
Hassan T. Badh
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Optical Properties ◽  
Thermal Annealing ◽  
Polymer Blend ◽  
Annealing Temperature ◽  
Energy Gap ◽  
Weather Conditions ◽  
Dielectric Constants ◽  
Casting Technique

"In this paper, we report upon preparation and optical properties of the polymer blend (50%PMMA:25%PVC:25%PS) thin films. The thin films have been prepared with specific ratios using the casting technique at normal weather conditions. The films were subjected to heat treatment in varying temperatures for three hours. The results showed that increase thermal annealing temperature leads to decrease values of the direct and indirect energy gap, but increase the extinction coefficient and optical conductivity. The refractive index, real and imaginary dielectric constants showed a heterogeneous behaviour. Thermal annealing by 80 oC and up leads to deformation the thin films.

scholarly journals Effects of Temperature on the Structural and Optical Preperties of AgGaSe2 Thin Films

1970 ◽  
Vol 33 (2) ◽  
pp. 179-188
Author(s):  
MRA Bhuiyan ◽  
DK Saha ◽  
SM Firoz Hasan
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Visible Region ◽  
Wavelength Region ◽  
Band Gap Energy ◽  
Post Deposition Annealing ◽  
X Ray ◽  
Glass Substrates ◽  
Academy Of Sciences ◽  
Post Deposition

In this study, AgGaSe2 (AGS) thin films were formed onto cleaned glass substrates by using the stacked elemental layer (SEL) deposition technique in vacuum. The films were prepared at the post-deposition annealing temperature from 100 to 350°C for 15 min duration. The atomic composition of the films was measured by energy dispersive analysis of X-ray (EDAX) method. The films ascertain the compositional uniformity. The X-ray diffraction (XRD) has been employed to study the structure of the films. The structures of the films are found to be polycrystalline in nature. The lattice parameters, grain size, strain and dislocation densities of the films were calculated. Optical characteristics of the films were ascertained by spectrophotometer in the photon wavelength ranging between 300 and 2500 nm. The transmittance was found to increase with the increase of annealing temperature. The transmittance falls steeply with decreasing wavelength. It revealed that AGS films have considerable absorption throughout the wavelength region from 400 to 800 nm. The optical band gap energy has been evaluated. Two possible direct allowed and direct forbidden transitions have been observed for all the AGS films in visible region. The former varied from 1.67 to 1.75 eV and the later from 2.05 to 2.08 eV, depending on the post-deposition annealing temperature of the films. DOI: 10.3329/jbas.v33i2.4101 Journal of Bangladesh Academy of Sciences, Vol. 33, No. 2, 179-188, 2009

Influence of Vacuum-Annealing Temperature on the Properties of Direct Current (DC) Magnetron Sputtered ZAO Thin Films

2019 ◽  
Vol 34 (1) ◽  
pp. 563-566
Author(s):  
Jundai Shi ◽  
Huidong Yang ◽  
Bo Huang ◽  
Baoyu Xu ◽  
Song Yu
Keyword(s):  
Thin Films ◽  
Direct Current ◽  
Annealing Temperature ◽  
Vacuum Annealing

synthesis of III-Nx-V1-x Thin Films by N Ion Implantation

2000 ◽  
Vol 647 ◽  
Author(s):  
K. M. Yu ◽  
W. Walukiewicz ◽  
W. Shan ◽  
J. Wu ◽  
J. W. Beeman ◽  
...  
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Ion Beam ◽  
Band Gap Energy ◽  
Implantation Dose ◽  
Processing Conditions ◽  
Nitrogen Implantation ◽  
Gap Energy ◽  
Activation Efficiency ◽  
Similar Processing

AbstractDilute III-Nx-V1-x alloys were successfully synthesized by nitrogen implantation in GaAs and InP. The fundamental band gap energy for the ion beam synthesized III-Nx-V1-x alloys was found to decrease with increasing N implantation dose in a manner similar to that commonly observed in epitaxially grown GaNxAs1-x and InNxP1-xthin films. The fraction of N occupying anion sites ("active" N) in the GaNxAs1-x layers formed by N implantation was thermally unstable and decreased with increasing annealing temperature. In contrast, thermally stable InNxP1-x alloys with N mole fraction as high as 0.012 were synthesized by N implantation in InP. Moreover, the N activation efficiency in InP was at least a factor of two higher than in GaAs under similar processing conditions. The low N activation efficiency (<20%) in GaAs can be improved by co-implanting Ga and N in GaAs.

LS-MOCVD of BSTO Thin Films Using Novel Ba and Sr Precursors

2003 ◽  
Vol 765 ◽  
Author(s):  
Hyun Goo Kwon ◽  
Youngwoo Oh ◽  
Jung Woo Park ◽  
Young Kuk Lee ◽  
Chang Gyoun Kim ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Strontium Titanate ◽  
Barium Strontium Titanate ◽  
Smooth Surface ◽  
Annealing Temperature ◽  
Dielectric Constants ◽  
Working Pressure ◽  
Barium Strontium ◽  
Ethyl Amine

AbstractWe report the synthesis of new precursors Ba(thd)2(tmeea) and Sr(thd)2(tmeea), where tmeea = tris[2-(2-methoxyethoxy)ethyl]amine, and the LS-MOCVD of barium strontium titanate (BSTO) thin films using these precursors. Thin films of BSTO were grown on Pt(111)/SiO2/Si(100) substrates by LS-MOCVD using the cocktail source consisting of the conventional Ti precursor Ti(thd)2(OiPr)2 and the new Ba and Sr precursors. As-grown films were characterized by SEM, XRD, XRF, and C-V measurement. BSTO films grown at 420°C were stoichiometric barium strontium titanate with very smooth surface morphology and their dielectric constants were found to be as large as 320. The dependence of composition, microstructure and the electrical properties of the BSTO films on the growth temperature, annealing temperature, and working pressure will be discussed.

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